Código HTML:
<HTML><HEAD><TITLE>International Rate Calculator</TITLE>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<STYLE type=text/css>BODY {
FONT-SIZE: 12px; FONT-FAMILY: Arial, Helvetica, sans-serif
}
TD {
FONT-SIZE: 12px; FONT-FAMILY: Arial, Helvetica, sans-serif
}
TH {
FONT-SIZE: 12px; FONT-FAMILY: Arial, Helvetica, sans-serif
}
.style1 {
FONT-SIZE: 10px
}
</STYLE>
<META content="MSHTML 6.00.6000.16481" name=GENERATOR></HEAD>
<BODY bgColor=#ffffff leftMargin=0 topMargin=0 MARGINHEIGHT="0" MARGINWIDTH="0"><!-- ImageReady Slices (sub-forcutting.html) -->
<TABLE cellSpacing=0 cellPadding=10 align=center bgColor=#ffffff border=0>
<TBODY>
<TR>
<TD>
<P style="FONT-WEIGHT: bold; FONT-SIZE: 14px">International Rate
Calculator</P>
<TABLE borderColor=#999999 height=120 cellSpacing=0 cellPadding=5
width=300 border=1>
<TBODY>
<TR>
<TD>
<P>
<FORM name=rates>
<P>From anywhere in the world your rate to:</P>
<P><SELECT
onchange="document.rates.rate.value='$ ' + ratelist.options[ratelist.selectedIndex].value; document.rates.mins.value=parseInt(9.950/ratelist.options[ratelist.selectedIndex].value);"
name=ratelist> <OPTION value="" selected>Select a Country</OPTION>
<OPTION value=0.020>United States</OPTION> <OPTION
value=0.020>Canada</OPTION>
<P> is <INPUT
onchange=document.rates.mins.value=rate.value; size=11 name=rate>
<INPUT type=hidden value=3149 name=rsid> .*</P></FORM>
<P class=style1> </P>
<P class=style1>* Rates are subject to change without notice. This
calculator does not include all rates.</P>
<P class=style1>Please note: International mobile carriers will
charge the caller for any error messages. These types of charges
will be deducted from your account at the end of each call.
</P></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></BODY></HTML> Este código es lo más cercano a lo que pretendo hacer, pero con 2 campos de texto y uno precio distinto por cada campo.